Draft: Demonstrating the effects of using AuthJobFinder in the Runner API helper

What does this MR do and why?

This is a demonstration of the issues I found trying to work on #490992

The AuthJobFinder doesn't allow for jobs to be canceling, running only. There's also some detailed handling re: job ehaders that we can't do because the AuthFinder uses exceptions for slow control (😠) instead of returning a detailed ServiceResponse object. I don't especially want to go down rabbit holes here, but we may want to make the refactor to allow us to move forward with using AuthJobFinder universally.

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Related to #490992